Until they learn not to, yes if they knot and turn they will start pulling. That's where it's good to have a partner to control the dog and keep it from pulling. That way you will be teaching the dog not to pull.
The next thing would be to teach the dog to lay down on its side with you doing the same like breeding dogs often do. That was you can roll onto you back and be more comfortable and have access to your pussy or penis to masturbate while tied. It would also allow for longer ties with the dog because he won't be pulling out, you'll stay tied until he "shrinks" and falls out.
IIRC there is a video here on ZV of a guy tied that way, or it was on the original version of ZV.